1. Field of the Invention
The present invention is related to equipment having a relatively movable shaft element, where a pressure-retaining seal establishes sealing contact with the relatively movable shaft element to retain a pressurized first fluid and partition the first fluid from a second fluid having lower pressure. Examples of relatively movable shaft elements include those that have relative rotation and/or relative reciprocation with respect to the pressure-retaining seal and/or relative lateral motion with respect to other components of the equipment.
The present invention is also related to a sealing assembly that applies the pressures of the first and second fluids to controlled locations on a backup ring in order to provide relative immunity to pressure-induced distortion, and in order to provide opposed axially acting hydraulic forces that substantially balance one another, allowing the backup ring to align on the shaft element and follow lateral deflection and runout of the shaft element, allowing the backup ring to define a small initial extrusion gap for the pressure-retaining seal, minimizing pressure-induced extrusion damage thereof.
More specifically, the present invention is related to a sealing assembly that applies the pressure of the first fluid to a projection outer surface of the backup ring to minimize pressure induced distortion of the backup ring, and applies extrusion resistant, self-aligning telescoping jackets to hydraulic area-defining face seals to accommodate the increased face seal extrusion gaps that can occur because of incorporating the projection outer surface.
2. Description of the Related Art
The most relevant prior art is described in commonly assigned U.S. Pat. No. 9,429,238, entitled “Dynamic Backup Ring Assembly,” and commonly assigned U.S. patent application Ser. No. 15/240,823, entitled “High Pressure Dynamic Sealing Arrangement.”